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Creationists do not define macroevolution in the same precise way that biologists do, allowing them to continually shift the goalposts as to what qualifies as macroevolution, thus allowing them to reject any and all evidence presented to them. Biologists generally define the boundary as change above the level of species, and there have been directly observed instances of speciation as well as many examples of recent speciation in the wild.

The honeysuckle maggot fly has recently been found to have directly arisen from a hybridization between the snowberry maggot fly and the blueberry maggot fly.

In 1905, in his patch of Oenothera lamarckiana, Hugo de Vries discovered an unusual specimen, and found that he was unable to crossbreed it with its parent-plants. He later named it O. gigas, and found that it had 2N=28, while its parent had 2N=14.

Regardless, first-person observation is simply not the only or even always the best sort of evidence relevant in science. Overwhelming physical evidence can often be more convincing and reliable than eye-witnesses in history: the same is true in science, only to a far greater degree because of the sheer amount of converging lines of evidence available to cross-check each other.

Creationists often note that "observation" is a step in the scientific method but neglect to mention that it refers to the initial observation of some situation that needs explanation (say, the diversity of species on earth today). Explaining those observations involves forming a hypothesis and testing its implications with evidence, which does not require literally watching something with eyeballs.

It is a known scientific fact that all plants on planet earth evolved from oceanic cyanobacteria, which gave rise to algae, which in turn gave rise to mosses, which began the process of transitioning from aquatic plants to land plants. Once this transition was made from the water to the land, diversification and speciation gave rise to all the land plants which exist today. This is a prime example of macro-evolution, although it did occur some 3 billion years ago and continues on to the present.